1. Field of the Invention
In general, the present invention relates to devices for marking a point, or a series of points, on a surface as determined by a tape measure, stud finder, level, or similar tool. More particularly, the present invention relates to the structures that interconnect the marking device to the casing of the tool.
2. Prior Art Description
There are many hand tools that measure distance, angles, depths, and the like. When these tools are used to measure a length of a surface, the user of the tool typically marks the measurement on that surface using a pencil or similar marker. Using both a measurement tool and a pencil typically requires a handyman to use both hands. Often, both hands are not free to use. Accordingly, many hand tools have been designed over the years that contain integral marking systems. These hand tools enable a handyman to both make a measurement and a mark using one hand in most cases. Such prior art tools also eliminate the need to carry and use a separate marker, such as a pencil or pen.
One of the most common measurement tools used by construction workers and handymen is the tape measure. The tape measure is typically used for measuring lengths along a surface. In the prior art, several tape measures have been designed with markers that can mark a measurement on a surface. Such prior art marks the surface in a variety of ways. Some tape measures have ink markers or graphite pencil markers that can be pressed against a surface to make a mark. Such prior art is exemplified by U.S. Pat. No. 4,015,337 to Taylor, entitled Combined Tape Measure And Marking Device; U.S. Pat. No. 4,296,554 to Hammerstrom, entitled Tape Measure and Marking Device, and U.S. Pat. No. 6,434,854 to MacColl, entitled Integrated Marking And Tape Measure.
In the prior art, other tape measures mark using a pin that cuts an indentation into the surface being measured. Such prior art is exemplified by U.S. Pat. No. 4,630,376 to Pentecost, entitled “Marking Device For A Tape Measure”. Still other tape measures contain chalk line mechanisms that utilize a chalk covered line to mark an underlying surface. Such prior art marking systems are exemplified by U.S. Pat. No. 7,086,176 to Scarbourough, entitled “Tape measure That Incorporates A Belt Type Marking Device”.
Each of the prior art marking techniques have disadvantages. Prior art marking systems that use ink, pencil graphite or chalk dust are prone to smearing. This is especially true if the underlying surface is wet. Furthermore, many ink-based marking systems have a tendency to permanently mark the underlying surface. This is especially true if the ink mark is left to dry over time. Accordingly, such marking systems cannot be employed on surfaces that are to remain pristine.
Similarly, marking systems that scratch a mark cannot be used on surfaces that are intended to remain pristine. Rather, such marking systems can only be used on unfinished soft surfaces, such as construction lumber. Furthermore, marking systems that scratch marks simply cannot be used on hard surfaces such as glass, ceramic, hardened steel, granite, or very soft surfaces, such as exposed fiberglass insulation.
Prior art marking systems that rely upon pencil graphite or chalk dust need a sharp point or a sharp edged wheel in order to make physical contact between the surface being marked and the graphite or chalk dust. That is, the pencil marker must run across the surface being marked, or the chalk line must be pressed by a wheel against the surface being marked. In either scenario, surface conditions, such as the presence of water, oil, frost, sawdust or the like can prevent the marking system from working and may even clog the marking system, causing it to fail. Furthermore, the pressure of the pencil point or wheel can create indents if a soft surface is being marked.
In U.S. Pat. No. 8,468,710, the applicant invented an improved system for marking surfaces that deposits a small mark of chalk dust without the marker physically contacting the surface being marked. This system eliminates many of the stated problems associated with prior art marking systems. The current invention improves upon the applicant's previous work by presenting improvements to the chalk dust marking system and the manner in which the dust marking system can be attached to existing tools. These improvements are contained within the present invention as described and claimed below.